Heretofore it has been well known to provide keyboard units having tactile switch assemblies that use snap dome switches as disclosed in U.S. Pat. No. 3,967,084. It has also been well known to provide membrane switch assemblies that additionally include snap dome switches to produce a tactile feedback and which include a flexible substrate on which circuitry is formed as in U.S. Pat. No. 4,463,234. This patent also makes it known to silk screen print conductive paint or ink onto the substrate. However, it requires a plurality of sheets of material in stacked form which increases the difficulty in aligning one sheet with another and also increases the overall thickness of the assembly. Additionally when stacking several sheets in an assembly, it is necessary to connect adjacent sheets by adhesive which may adversely affect the reliability of the assembly.